Protozoa are characterized as what type of organisms?

• A. Multicellular
• B. Photosynthetic
• C. Single-celled
• D. Filamentous

Answer: (C)

Protozoa are single-celled, eukaryotic organisms. They carry out all life processes within one cell, so they are not organized into multiple tissues or body parts like many plants and animals. This single-cell nature is why they are described as unicellular. They are typically not photosynthetic organisms; most protozoa obtain energy by consuming other organisms or organic matter, though some can harbor photosynthetic symbionts. They also don’t grow as filamentous networks; filamentous forms are more typical of fungi or certain algae. Examples like Amoeba and Paramecium illustrate organisms that function as a whole unit within a single cell.